Through-substrate via (tsv) testing

ABSTRACT

Various embodiments comprise apparatuses and methods for testing and repairing through-substrate vias in a stack of interconnected dice. In various embodiments, an apparatus is provided that includes a number of through-substrate vias to couple to one or more devices, at least one redundant through-substrate via to allow a repair of the apparatus, and a pair of pull-up devices coupled to the through-substrate vias and the redundant through-substrate via to provide a high-data value to the first end of the respective through-substrate vias. A test register is coupled the second end of each of the through-substrate vias and the redundant through-substrate via to store a received version of the high-data value. A comparator compares the high-data value with the received version of the high-data value to test the through-substrate vias for short-circuit connections.

PRIORITY APPLICATION

This application is a divisional of U.S. application Ser. No.13/411,167, filed Mar. 2, 2012, which is hereby incorporated byreference in its entirety.

BACKGROUND

Computers and other electronic systems, for example, digitaltelevisions, digital cameras, and cellular phones, often have one ormore memory devices to store information. Increasingly, memory or otherdevices are being reduced in size or have devices stacked to achieve ahigher density of storage capacity within a similar footprint. However,stacked devices must still be robust in die-to-die communications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a microelectronics package havinga number of stacked and interconnected integrated circuit dice;

FIG. 2 shows a cross-sectional view of a microelectronics package havinga number of stacked and interconnected integrated circuit dice withinterconnect defects;

FIG. 3 shows an illustrative embodiment for TSV testing using a scanchain arrangement;

FIG. 4 shows an embodiment of a portion of a transmitter/receivercircuit used for TSV testing in the scan chain of FIG. 3;

FIG. 5 shows another embodiment of a portion of a transmitter/receivercircuit used for TSV testing in the scan chain of FIG. 3 andincorporating a redundant TSV;

FIG. 6 shows an embodiment of a circuit used for TSV testing includingcircuitry for testing TSV faults, including shorts and opens;

FIG. 7 shows a method for performing open and short testing on TSVs;

FIG. 8A shows an embodiment of a default switch connection for a numberof TSVs and including redundant TSVs;

FIG. 8B shows an embodiment of the switch connection of FIG. 8A afterrepairing two defective TSVs;

FIG. 9 illustrates an embodiment of a method for repairing TSVs; and

FIG. 10 shows a block diagram of a system embodiment, including a memorydevice.

DETAILED DESCRIPTION

In order to increase integrated circuit device density within a givenarea (e.g., a footprint on an electrical device or board), integratedcircuit dice are often stacked on top of one another. One such examplemay be memory cards where a number of dice are stacked to increase anoverall amount of memory. Each die has a number of integrated circuitdevices fabricated on a substrate. However, each die within the stackfrequently needs to communicate with other dice in the stack (e.g.,slave dice typically need to communicate with a master die to performtheir functions). Such stacks may be interconnected from one side of thesubstrate to the other. The interconnections include through-substratevias (TSVs). When the substrate comprises silicon, the interconnectionsmay also be referred to as through-silicon vias. If the TSVs aredefective (e.g., are open or shorted), electrical communications may notoccur throughout the stack as intended.

Referring now to FIG. 1, a cross-sectional view of a microelectronicspackage 100 having a number of stacked and interconnected integratedcircuit dice is shown. The stacked and interconnected dice may form atleast a portion of a microelectronics package. The microelectronicspackage 100 is shown to include four integrated circuit dice. In thisexample, the four integrated circuit dice include a master die 101, andthree slave dice 103A, 103B, 103C, however, any number of integratedcircuit die may be incorporated. The three slave dice 103A, 103B, 103Cmay be identified individually as the first, the second, and the thirdslave die, respectively. The identification as first, second, and thirddoes not necessarily indicate any type of order or importance and issimply provided for ease in identification throughout the variousembodiments.

In other embodiments, the microelectronics package 100 may contain anyother desired number of integrated circuit dice. Each of the integratedcircuit dice has a first surface 105A and a second surface 105B. Anarrow 110 indicates a normal orientation of the dice in which the firstsurface 105A is located at an upper surface of the substrate where theupper surface is generally used during fabrication of integrated circuitdevices on the substrate. That is, the upper surface of the substrate isthe surface used to form integrated circuit devices on a die.

A number of through-substrate vias (TSVs) 107 is shown on each of thefour dice, including the master die 101, and the slave dice 103A, 103B,103C. The TSVs 107 may also be referred to as through-silicon vias,depending upon the substrate type (e.g., silicon or other elementalsemiconductors, compound semiconductors, or other substrate types knownin the art) from which the dice are formed. The TSVs 107 may be formedfrom the first surface 105A through the integrated circuit die to thesecond surface 105B (or alternatively, from the second surface 105B tothe first surface 105A). In operation, the TSVs 107 can be selectivelyconnected to certain metallization layers within the die and thereforeallow an interconnection from, for example, integrated circuit devicesformed on the first surface 105A and through to the second surface 105Bof the master die 101, to connect to one or more of the slave dice 103A,103B, 103C, in the stack.

Each of the TSVs 107 has a conductive bonding pad 109 formed on eitherend of the TSVs 107. Adjacent ones of the dice are electrically coupledby a conductive electrical connector 113 that is placed or formedbetween the conductive bonding pads. The conductive electrical connector113 may be, for example, a wirebond, a solder ball, conductive tape, aC4 interconnect (Controlled Collapse Chip Connection), or other suitableelectrical connector. The conductive electrical connectors 113 thereforeform electrical interconnects 111 between each of the adjacent dice. Theconductive bonding pads 109 on the first surface 105A of the master die101 may be accessible to form an external interface 115. The externalinterface 115 allows interconnection with other devices such as, forexample, a microprocessor. The external interface may be connected topins (not shown) of the microelectronic package by bonding wiresallowing accessibility from outside the package. Similarly, theconductive bonding pads 109 on the second surface 105B of the thirdslave die 103C form an external slave interface 121 that may be used,for example, to interface with other devices or, alternatively, allowinterconnection with other slave dice in a larger stack.

In FIG. 2, a cross-sectional view showing a microelectronics package 200having a number of stacked and interconnected integrated circuit dicewith interconnect defects indicates various examples of the types ofdefects that may occur when such stacks are formed. Any one of thesevarious defect types may cause electrical communication issues betweenthe master die 101 and one or more of the slave dice 103A, 103B, 103C.For example, a malformed conductive electrical connector 201 has failedto complete an electrical pathway between adjacent ones of the TSVs 107.The malformed conductive electrical connector 201 may result from anincomplete wirebond or an undersized solder ball. In another defecttype, an open TSV 203 has been incompletely formed between the firstsurface 105A and the second surface 105B of the second slave die 103B,thus presenting a missing connection (e.g., an open circuit) between thefirst slave die 103A and the second slave die 103B. A misalignedconductive electrical conductor 205 also prevents an improper electricalinterconnect between the master die 101 and the first slave die 103A.The misaligned conductive electrical conductor 205 may be, for example,a C4 interconnect that failed to collapse properly. In still anotherdefect type, a shorted TSV 207 provides an electrical connection betweenthe TSV and the substrate of the master die 101. The shorted TSV 207 maycause drive and leakage issues depending upon a resistance value of theshort and the short-tolerance or design of the connected electricaldevice.

Referring now to FIG. 3, an illustrative embodiment for TSV testingusing a scan-chain arrangement 300 is shown. The scan-chain arrangementmay be used to test each of the TSVs in the microelectronics package100, 200 of FIG. 1 and FIG. 2. The scan-chain arrangement 300 is shownto include test pattern transmission and receive circuitry, includingtransmission circuitry 309 in the master die 101 and receive circuitry311 in each of the slave dice 103A, 103B, 103C. Note that the receivecircuitry 311 is only shown in the third slave die 103C to avoidobscuring detail in the figure. However, a person of ordinary skill inthe art will understand that the same or similar types of circuitry maybe replicated in the first slave die 103A and the second slave die 103Bof FIG. 1 as well.

The transmission circuitry 309 is electrically coupled to the receivecircuitry 311 through a number of electrical communication paths 305established through the TSVs. A person of skill in the art, upon readingthe disclosure provided herein, will further understand that thetransmission circuitry 309 may also receive data, and similarly, thereceive circuitry 311 may also transmit data. Therefore, the termstransmit and receive are provided simply as identifiers for brevity ofnotation and are not intended to indicate a sole function of therespective devices. Thus, in some embodiments, the transmissioncircuitry 309 and/or the receive circuitry 311 may operate as atransceiver.

Overall, the transmission circuitry 309 sends test data to the receivecircuitry 311 through the electrical communication paths 305. Thereceive circuitry 311 receives the test data and then stores andtransmits the test data back to the transmission circuitry 309. Acomparison is then made through a comparator 315 between the test datasent and the test data later received. If there are any differencesbetween the test data sent and the test data later received, one or moredefective TSVs can be identified.

The comparator 315 may be implemented as, for example, an operationalamplifier-based voltage comparator or a software-based comparator, suchas a null-level detector. Although the comparator 315 is shown as beinglocated within the master die 101, the comparator 315 may be located inany device interconnected with the master die 101. Further, thecomparator 315 may form a portion of another device in electricalcommunication with the master die 101, such as a coupled controller ormicroprocessor.

Each connective string 313A, 313B, . . . , 313 n , of theserially-connected ones of the TSVs 107 has a respective transceiver301A, . . . , 301 n (e.g., master transceivers) located within themaster die 101 and a respective transceiver 303A, . . . , 303 n (e.g.,slave transceivers) located in the third slave die 103C. A person ofordinary skill in the art will recognize that, depending upon aparticular operation or location during testing, the transceivers mayfunction as either a transmitter or a receiver. The transceivers 301A, .. . , 301 n and the transceivers 303A, . . . , 303 n may comprise anumber of components known independently in the art including, forexample, operational amplifiers, buffers, and follower circuitry.Further, the transceivers 301A, . . . , 301 n and the transceivers 303A,. . . , 303 n may be fabricated or otherwise formed on the various diceduring formation of other integrated circuit devices on the respectivedice.

The (serial) connections to the TSVs 107 may be tested as follows. Eachof the transceivers 301A, . . . , 301 n in the master die 101 writes apredetermined test pattern to the transceivers 303A, . . . , 303 n inthe third slave die 103C through each of the connective strings 313A,313B, . . . , 313 n. Each of the respective transceivers 303A, . . . ,303 n receives the predetermined test pattern and stores the test datain a test register associated with the respective ones of thetransceivers 303A, . . . , 303 n.

The test registers and the transceivers 303A, . . . , 303 n areelectrically coupled with one another to form a scan chain 307. The testdata from each of the test registers and transceivers 303A, . . . , 303n are forwarded to the last test register and its respective transceiver303 n. In one embodiment, the stored test data from each of the testregisters may be scanned using only the last transceiver 303 n in thethird slave die 103C, back to the master die 101 through the lastconnective string 313 n. Since the data from the test pattern are onlytransmitted back through the last connective string 313 n, the lastconnective string 313 n may be considered to be a more usefulcommunication string. However, any one of the connective strings may beused to transmit data. Thus, each of the TSVs 107 within the lastconnective string 313 n should be in electrical communication with oneanother so that proper and thorough testing can occur. Consequently, thetransmission and receive circuitry associated with at least the lastconnective string 313 n, being the more useful communication string, maybe modified to ensure functionality of the associated TSVs.

Once the transceivers 301A, . . . , 301 n in the master die 101 receivethe data from each of the transceivers 303A, . . . , 303 n, the data areeach compared with the originally transmitted test pattern forverification of transmission/receipt accuracy. If a determination ismade that the received test data match the transmitted test pattern,then each of the connections between the TSVs 107 should be intact(e.g., as shown in FIG. 1). If a determination is made that the receivedtest data does not match the transmitted test pattern, then a repair islikely needed to one or more of the TSVs 107 in one or more of theconnective strings 313A, 313B, . . . , 313 n. The repair is performed bysubstituting a subsequent TSV for the TSV found to be defective. Detailsof various types of TSV testing and repairs are discussed below. Oncerepairs are made, the entire test process may be run again until eitherthe test passes or no further repairs can be made.

With reference now to FIG. 4, an illustrative embodiment of a portion ofa transmitter/receiver circuit 400 used for TSV testing in the scanchain of FIG. 3 is shown. As with FIG. 3, the portion of thetransmitter/receiver circuit 400 shows only circuitry associated withthe master die 101 and the third slave die 103C. In some embodiments,the first slave die 103A and the second slave die 103B each may havecircuitry similar to or identical to that of the third slave die 103C.However, only the master die 101 and the third slave die 103C are shownso as not to obscure the figure.

The TSV 107 is coupled on opposing ends to the transceivers 301A, 303A,the transceivers 301B, 303B, and to a pair of pass transistors 401. Asdiscussed above with reference to FIG. 3, a test register 403 isassociated with each of the transceivers. However, the portion of thetransmitter/receiver circuit 400 may have a high failure probability ifthere are any defects with the TSV 107 as discussed above with regard toFIG. 2. For example, if the TSV 107 is open, then the test pattern datatransmitted from the transceiver 301A cannot be received by thetransceiver 303B in the third slave die 103C. Further, if the TSV 107 isshorted to the substrate, for example, as indicated by the shorted TSV207 of FIG. 2, then the transceiver 301A may not be able to sourcesufficient power for the test pattern data to be transmitted.

FIG. 5 shows another embodiment of a portion of a transmitter/receivercircuit used for TSV testing in the scan chain of FIG. 3 andincorporating a redundant TSV 501. The redundant TSV 501, in parallelwith the TSV 107, reduces the probability of TSV failure due to an openconnection. Should the TSV 107 fail due to, for example, a malformedconductive electrical connector 201, a misaligned conductive electricalconductor 205, or an open TSV 203, as shown in FIG. 2, then theredundant TSV 501 provides a communication pathway from the master die101 to the third slave die 103C.

However, the redundant TSV 501 may not eliminate a TSV failure due to ashort between either the TSV 107 or the redundant TSV 501 to thesubstrate. If either of the shorts has enough resistance, such that thetransceiver 301A can handle the short (e.g., by sourcing sufficientpower to the TSV), then testing for shorts in the TSVs may not benecessary. Of course, testing for open TSVs may still be neededdepending upon the design of interconnect circuitry and a location ofwhere any open TSVs are located. Determining whether the transceiver301A can handle the short will depend upon, for example, various designparameters associated with integrated circuit devices formed on thevarious dice. Such techniques for designing integrated circuit devicesare known independently in the art. If, however, shorts cannot betolerated on the TSVs, then another circuit may be considered.

Referring now to FIG. 6, an embodiment of the circuit used for TSVtesting including a portion of circuitry 600 for testing TSV faults,including shorts and opens, is shown. The portion of the circuitry 600is similar to that shown in FIG. 5. However, the redundant TSV 501 isnot coupled in parallel with the TSV 107. Rather, the transceiver 301Aand the transceiver 303A each have a redundant transceiver 601 and aredundant transceiver 603 that are coupled in parallel. The redundanttransceiver 601 and the redundant transceiver 603 are also electricallycoupled to the redundant TSV 501. Further, on the output of each of thetransceivers, a weak pull-up device 605A, 605B is included that may beenabled during either open or short testing. Each of the redundanttransceiver 601 and the redundant transceiver 603 further includes apass gate 607A, 607B, respectively, coupled in series between therespective redundant pass gate and the associated subsequent one of thetransceiver 301B and the transceiver 303B, each of which is coupled to arespective test register 403A, 403B.

During operation of the scan-chain arrangement 300 of FIG. 3, if thetest pattern data received back from the third slave die by the masterdie 101 is different from the transmitted test pattern data, the TSV 107may be tested for either an open connection or a shorted connection. Asnoted above, the portion of the transmitter/receiver circuit 500 of FIG.5 may be used to test for open connection in the TSV 107. However, theportion of the circuitry 600 can test for either an open connection or ashorted connection.

Both open and short testing of the TSVs can be self enabled (e.g., usinga built-in self test (BIST)) upon power up of the devices, for each diein the stack. The TSV testing may begin from either the master die 101with results stored in the test register 403A on the third slave die103C side, or, alternatively, the testing may begin from the third slavedie 103C with results being stored in the test register 403B on themaster die 101.

For example, in one embodiment of short testing, the transceiver 301Aand the redundant transceiver 601 are disabled and one of the associatedweak pull-up devices 605C, 605D is enabled. The transceiver 303A, theredundant transceiver 603, and their associated weak pull-up devices605C, 605D, are also disabled. The data are passed through either theTSV 107 or the redundant TSV 501, through to the third slave die 103C,with the data then being stored in the test register 403A. A comparisonis made of the data stored in the test register 403A with originaltransmitted data.

In another embodiment of short testing, the transceiver 303A and theredundant transceiver 603 are disabled and the associated one of theweak pull-up devices 605A, 605B, is enabled. The transceiver 301A, theredundant transceiver 601, and their associated weak pull-up devices605C, 605D, are disabled. In this case, the data are again passedthrough either the TSV 107 or the redundant TSV 501 and stored in thetest register 403B. A comparison is made of the data stored in the testregister 403B with original transmitted data.

The short testing may then conducted for each of the connective strings313A, 313B, . . . , 313 n (e.g., the serial TSV paths). Alternatively,the short testing may only be conducted for the last connective string313 n, identified earlier as a potential critical connective string.

In a more detailed illustrative embodiment of a test situation where thetransceiver 301A and the transceiver 303A are enabled, the associatedweak pull-up devices 605C, 605A are disabled. An open connection in theTSV 107 prevents the test program data transmitted from the master die101 from reaching the third slave die 103C, as discussed above. However,should the TSV 107 fail due to a suspected short, short testing may beperformed as follows.

The transceiver 301A is disabled. The weak pull-up device 605C and thepass transistor 401A of the third slave die 103C are enabled to providea test path from the master die 101 through the TSV 107 and to the testregister 403A of the third slave die 103C. As indicated in FIG. 6, thetest path places the master die 101 end of the TSV 107 at a high-datavalue (e.g., at V_(DD)). If the TSV 107 is not shorted, a resultanthigh-data value is recorded in the test register 403A. However, if theTSV 107 is shorted, a value less than the high-data value is recorded inthe test register 403A.

As discussed above, the test value stored in the test register 403A maybe compared with the high-data value and a determination made whetherthe values are the same. If the value recorded in the test register 403Ais less than a predetermined percentage of the high-data value, the TSV107 is presumed to be shorted. If the TSV is shorted, a determination ofwhether the TSV 107 needs to be replaced with a redundant TSV dependsupon whether the value of the resistance can be tolerated within thecircuit. The toleration of resistance is discussed in more detail below.

If the TSV 107 is determined to be defective, due to either anopen-circuit or a short-circuit condition, the redundant TSV 501 may besubstituted for the TSV 107. The transceiver 301A and the transceiver303A are then disabled and the redundant TSV 501 is tested in a mannersimilar to that discussed above with reference to the TSV 107 testing.

For short testing, the redundant transceiver 601 is disabled. The weakpull-up device 605D and the pass gate 607A of the third slave die 103Care enabled to provide a test path from the master die 101 through theredundant TSV 501 and to the test register 403A of the third slave die103C. As indicated in FIG. 6, the test path places the master die 101end of the redundant TSV 501 high (e.g., at V_(DD)). If the redundantTSV 501 is not shorted, a resultant high-data value is recorded in thetest register 403A. However, if the redundant TSV 501 is shorted, avalue less than the high-data value is recorded in the test register403A. As discussed above, the test value stored in the test register403A may be compared with the high-data value and a determination madewhether the values are the same. If the value recorded in the testregister 403A is less a predetermined percentage than the high-datavalue, the redundant TSV 501 is presumed to be shorted.

The design of the weak pull-up devices may depend upon a size of thestack (e.g., the total number of one or more master devices and theslave dice), and the lowest value of short resistance that is consideredacceptable for proper functionality of the various integrated circuitdevices, perhaps based on a predicted number of bit read or write errorsto be expected over time. Another factor to be considered is thecumulative effect of each of the pull-up devices coupled to a givenconnective string of TSVs. For example, if a weak pull-up device in eachof the slave dice 103A, 103B, 103C, is enabled simultaneously (e.g.,when the testing of different dice coincides), the sourced power fromthe combination of the three pull-up devices may be significantlygreater than if a single pull-up device is enabled separately. That is,the weak pull-up device in one die may get assistance from one or moreother pull-up devices located on other dice in the stack. Thus, the sizeof the weak pull-up device may need to be considered. Calculations anddeterminations for the strength of a pull-up device are knownindependently in the art.

In other embodiments, the weak pull-up device may be designed toincrease power as needed during short testing of the TSVs. For example,the pull-up device may start at a normal power setting. Depending uponthe result stored in the test register, the weak pull-up device may beprogrammed or otherwise configured (e.g., during manufacture) toincrease power on subsequent testing should initial results proveinconclusive. The power setting may be increased in terms of integralpowers (e.g., 2 times, 4 times, 8 times, etc.) or in accordance withsome other scheme.

FIG. 7 shows a method 700 for performing open and short testing on TSVs.With continuing reference to FIG. 6, at operation 701, a decision toperform an open test is made. This may take the form of anexternally-initiated test, or as part of a built-in self test, forexample. At operation 703, a test pattern is applied to the first end107-1 of the TSV 107. The test pattern is received from the second end107-2 of the TSV 107 at operation 705 and stored in the test register403A at operation 707. The stored test pattern is then compared with theapplied test pattern at operation 709. The comparison may be made with,for example, the comparator 315 of FIG. 3.

A determination is made whether the stored and applied test patterns arethe same at operation 711. If the test patterns are not the same, theTSV 107 is presumably open or otherwise defective and the open test isended at operation 713. Other TSVs may be tested by performing themethod 700 again, beginning at operation 701. If the test patterns arethe same, a determination is made that the TSV 107 is not open and themethod 700 continues at operation 715 where the TSV 107 is tested for ashort-connection to the substrate.

At operation 717, a high-data value is applied to the first end 107-1 ofthe TSV 107. As discussed above, the high-data value is developed byenabling the weak pull-up device 605C. The data value is then receivedfrom the second end 107-2 of the TSV 107 at operation 719 and stored inthe test register 403A at operation 721. The received-data value and thehigh-data value at then compared at operation 723. A determination ismade at operation 725 whether the received-data value matches thehigh-data value with a predetermined percentage, as discussed above. Ifso, the short test is ended at operation 727. If the two data values donot match within the predetermined percentage, TSV repair operationsensue at operation 729. TSV repair is now discussed in detail withreference to FIGS. 8A, 8B, and 9.

Referring now to FIG. 8A, an explanation of a repair methodology isprovided. The repair methodology may be invoked should any of the TSVs107 or the redundant TSVs 501 be open or shorted. FIG. 8A shows anembodiment of a default switch connection for a number of TSVs,including two redundant TSVs 805. In this embodiment, 12 TSVs are shown.Each of the TSVs has a three-position switched input 801 and athree-position switched output 803. The three positions may beconsidered to be three programmable I/Os (input/outputs). Each of theswitches can be, for example, a multiplexer, a data selector, or varioustypes of transconductance devices. In some embodiments, each of theswitches may be a fused link.

In an illustrative example, the configuration of the TSVs and associatedswitched I/Os of FIG. 8A may be used with memory devices. With a memorydevice, data (DQ) lines may include eight TSVs for data read (DR) lines,two TSVs for data rising and falling clock signals (e.g., DInR and DInF,respectively), and two redundant TSVs. In this embodiment, TSV 0 and TSV1 are provided for the DInR and DInF signals, respectively; TSV 2through TSV 9 are provided for the DR lines (DR0 through DR7), with thetwo redundant TSVs 805, identified in FIG. 8A as TSV 10 and TSV 11.

In this embodiment, having two redundant TSVs 805 per group allows up totwo repairs to be made per group. In some embodiments, the redundantTSVs 805 may be placed at one end of the group so that any shift used toreplace a defective TSV with a redundant TSV is unidirectional, asdescribed below with reference to FIG. 8B. The unidirectional shiftsimplifies the overall logic by shifting all of the switch positionsneeded in one direction and not requiring the repairs to wrap to thebeginning of the TSV chain.

The default switch position for the two redundant TSVs 805 is a groundedinput and a non-connected output. To determine whether a repair isneeded, the TSVs are first tested for proper conductivity using the scanchain, discussed with reference to FIG. 3 through FIG. 6. If the scanchain test determines that a bad TSV is present, a repair may be made byrerouting the I/O signals from the bad TSV to an adjacent TSV by makingappropriate changes on the switched inputs 801 and the switched outputs803.

Referring now to FIG. 8B, an example of the switch connection of FIG. 8Ais shown after two defective TSVs have been repaired. In the example ofFIG. 8B, TSV 7 and TSV 10 have been found to be defective. In thisexample, the initial test for proper conductivity using the scan chainmethodology would first find TSV 7 to be defective (since TSV 10 is oneof the redundant TSVs and would not initially be tested). Therefore,since TSV 7 is defective, data formerly entering TSV 7 are now shiftedto TSV 8 and the I/Os of TSVs subsequent to TSV 8 are shifted as well.The connection from DR5 through the switched input 801-7 to TSV 7 hasbeen disabled or removed. Similarly the switched output 803-7 of TSV 7to DRO5 has also been disabled or removed. The data line, DR5, is nowconnected through the switched input 801-8 to TSV 8. The output of TSV8, formally connected to DRO6, is now switched through the switchedoutput 803-8 to DRO5. The data line DR6, formally connected to TSV 8, isrerouted to TSV 9 through input switch 801-9 and the output of TSV 9 isrerouted to DRO6 through output switch 803-9.

Once TSV 7 has been repaired, the scan chain process is again executedto check for any further defective TSVs. In this example, the secondround of the scan chain methodology has determined that TSV 10, one ofthe redundant TSVs 805, is also defective. Ordinarily, if none of theTSVs were found to be defective, the scan chain methodology would onlyneed to be executed once. However, in this case, since TSV 7 was foundto be defective, the scan chain methodology was executed a second timeand detected one the redundant TSVs 805 was also defective. Thus thesubsequent switching occurring after TSV 7 required the second redundantTSV 805 (TSV11) to be used for a final repair. Thus, the data line DR7that was shifted from TSV 9 is now shifted to TSV 11 through theswitched input 801-11. The output from TSV 11 is switched to DRO7through the switched output 803-11.

With redundant TSVs 805, up to two repairs can be made to account fortwo defective TSVs. As will be understandable to a person of skill inthe art upon reading the disclosure provided herein, more or less thantwo redundant TSVs 805 may be incorporated for each group depending uponthe degree of protection desired for a particular scan line coupled withthe available real estate on a given integrated circuit die.

An increased number of useful pathways may benefit from an increasednumber of redundant TSVs. For example, if additional redundant TSVs arecontemplated, the three-position switched inputs 801 and thethree-position switched outputs 803 may be used with an increased numberof redundant TSVs.

FIG. 9 illustrates an embodiment of a method 900 for repairingthrough-substrate vias. An identification of the defective TSV isconfirmed at operation 901. At operation 903, the associated input andthe output switches are each removed or disabled from the defective TSV.The inputs and outputs previously connected to the defective TSV areshifted to a subsequent TSV in operation 905.

A determination is made at operation 907 as to whether the subsequentTSV is a redundant TSV. If the subsequent TSV is a redundant TSV, thenthe repair is completed the method 900 is terminated at operation 909.At this point, the newly-switched in TSV (the redundant TSV) may be openand short tested by returning to the method 700 of FIG. 7. However, ifthe subsequent TSV is not a redundant TSV, then the method 900 continuessince the subsequent TSV was previously connected to an external circuitthrough its respective I/O switches. At operation 911, inputs andoutputs of the subsequent TSV are shifted to those of the nextsubsequent TSV. Thereafter, the method 900 continues until either aredundant TSV is reached at operation 907 or until the circuit exhaustsall available redundant TSVs.

With reference now to FIG. 10, a block diagram of an illustrativeembodiment of an apparatus in the form of an electronic system 100including one or more memory devices is shown. The memory device may becomprised of stacked integrated circuit dice, as discussed above. Thesystem 1000 may be used in devices such as, for example, a personaldigital assistant (PDA), a laptop or portable computer with or withoutwireless capability, a web tablet, a wireless telephone, a pager, aninstant messaging device, a digital music player, a digital camera, orother devices that may be adapted to transmit or receive informationeither wirelessly or over a wired connection. The system 1000 may beused in any of the following systems: a wireless local area network(WLAN) system, a wireless personal area network (WPAN) system, or acellular network.

The system 1000 of FIG. 10 is shown to include a controller 1003, aninput/output (I/O) device 1011 (e.g., a keypad, a touchscreen, or adisplay), a memory device 1009, a wireless interface 1007, and a staticrandom access memory (SRAM) device 1001 coupled to each other via a bus1013. A battery 1005 may supply power to the system 1000 in oneembodiment. The memory device 1009 may include a NAND memory, a flashmemory, a NOR memory, a combination of these, or the like.

The controller 1003 may include, for example, one or moremicroprocessors, digital signal processors, micro-controllers, or thelike. The memory device 1009 may be used to store informationtransmitted to or by the system 1000. The memory device 1009 mayoptionally also be used to store information in the form of instructionsthat are executed by the controller 1003 during operation of the system1000 and may be used to store information in the form of user dataeither generated, collected, or received by the system 1000 (such asimage data). The instructions may be stored as digital information andthe user data, as disclosed herein, may be stored in one section of thememory as digital information and in another section as analoginformation. As another example, a given section at one time may belabeled to store digital information and then later may be reallocatedand reconfigured to store analog information. The controller 1003 mayinclude one or more of the novel memory devices described herein.

The I/O device 1011 may be used to generate information. The system 1000may use the wireless interface 1007 to transmit and receive informationto and from a wireless communication network with a radio frequency (RF)signal. Examples of the wireless interface 1007 may include an antenna,or a wireless transceiver, such as a dipole antenna. However, the scopeof the inventive subject matter is not limited in this respect. Also,the I/O device 1011 may deliver a signal reflecting what is stored aseither a digital output (if digital information was stored), or as ananalog output (if analog information was stored). While an example in awireless application is provided above, embodiments of the inventivesubject matter disclosed herein may also be used in non-wirelessapplications as well. The I/O device 1011 may include one or more of thenovel stacked devices described herein. Further, various embodimentsdescribed in the figures can be included as part of various ones of thedevices on the bus of FIG. 10.

The various illustrations of the methods and apparatuses are intended toprovide a general understanding of the structure of various embodimentsand are not intended to provide a complete description of all theelements and features of the apparatuses and methods that might make useof the structures, features, and materials described herein.

In various embodiments, an apparatus is provided to test TSVs andincludes at least one transceiver to apply a test pattern to a first endof the TSVs. At least one receive transceiver receives the test patternfrom a second end of the TSVs and a test register stores the testpattern. A comparator compares the stored test pattern with the appliedtest pattern to test the TSVs for open-circuit connections.

In at least some of the embodiments, the apparatus also includes atleast one redundant through-substrate via. A pull-up device coupled tothe first ends of each of the at least one redundant TSV provides ahigh-data value to the redundant TSVs. A redundant master transceiverand a redundant slave transceiver are also coupled to the first andsecond ends, respectively, of each of the redundant TSVs. A redundantslave transceiver is coupled to the second end of redundant TSVs and isfurther coupled to the test register.

In various embodiments, an apparatus is provided that includes a numberof TSVs to couple to one or more devices, at least one redundant TSV toallow a repair of the apparatus, and a pair of pull-up devices coupledto the TSVs and the redundant TSV to provide a high-data value to thefirst end of the respective TSVs. A test register is coupled the secondend of each of the TSVs and the redundant TSV to store a receivedversion of the high-data value. A comparator compares the high-datavalue with the received version of the high-data value to test the TSVsfor short-circuit connections.

In some embodiments of the apparatus, at least one master transceiverapplies a test pattern to a first end of the TSVs. At least one slavetransceiver receives the test pattern from a second end of the TSVs.

In various embodiments, an apparatus is provided that includes a numberof TSVs and at least an integral number, n, of redundant TSVs. Aswitched input and a switched output is coupled to respective inputs andoutputs of each of the TSVs and the redundant TSVs. Each of the switchedinputs and the switched outputs may have, for example, three switchableinputs and three switchable outputs. The switched inputs and switchedoutputs are arranged to switch out a defective TSV with a subsequentlylocated TSV.

In various embodiments, a method for testing through-substrate vias isprovided that includes applying a test pattern to a first end of thethrough-substrate vias, receiving the test pattern from a second end ofthe through-substrate vias, and storing the received test pattern. Theapplied test pattern is compared with the received test pattern. Adetermination is made whether the through-substrate vias have an openconnection based on a result from the comparison.

In some embodiments of the method, based on a determination that one ormore of the TSVs do not have an open connection, a short-connection testis performed that includes applying a high-data value to the first endof the TSVs, receiving a data value from the second end of the TSVs,storing the received-data value, and comparing the received-data valuewith the high-data value. A determination is made whether the TSVs havea short connection based on a result from the comparison.

In various embodiments, a method is provided for repairing a defectiveTSV. The method includes indentifying a defective TSV, disabling aninput and an output from the defective TSV, and shifting the input andthe output from the defective TSV to a respective input and output of asubsequent TSV.

In some embodiments of the method, a determination whether thesubsequent TSV is a redundant TSV. In some embodiments, based on adetermination that the subsequent TSV is a redundant TSV, the TSV repairis terminated.

In some embodiments of the method, based on a determination that thesubsequent TSV is not a redundant TSV, the input and output from thesubsequent TSV is shifted to a respective input and output of a nextsubsequent TSV.

The apparatuses of the various embodiments may include or be includedin, for example, electronic circuitry used in high-speed computers,communication and signal processing circuitry, single or multi-processormodules, single or multiple embedded processors, multi-core processors,data switches, and application-specific modules including multilayer,multi-chip modules, or the like. Such apparatuses may further beincluded as sub-components within a variety of electronic systems, suchas televisions, cellular telephones, personal computers (e.g., laptopcomputers, desktop computers, handheld computers, tablet computers,etc.), workstations, radios, video players, audio players, vehicles,medical devices (e.g., heart monitors, blood pressure monitors, etc.),set top boxes, and various other electronic systems.

A person of ordinary skill in the art will appreciate that, for this andother methods (e.g., programming or read operations) disclosed herein,the activities forming part of various methods may be implemented in adiffering order, as well as repeated, executed simultaneously, orsubstituted one for another. Further, the outlined acts and operationsare only provided as examples, and some of the acts and operations maybe optional, combined into fewer acts and operations, or expanded intoadditional acts and operations without detracting from the essence ofthe disclosed embodiments.

The present disclosure is therefore not to be limited in terms of theparticular embodiments described in this application, which are intendedas illustrations of various aspects. Many modifications and variationscan be made, as will be apparent to a person of ordinary skill in theart upon reading and understanding the disclosure. For example, althougheach of the embodiments discussed TSVs used to communicate throughvarious dice, the same or similar arrangements may be used tocommunicate from one side of a die to circuitry formed on the back sideof the same die. Functionally equivalent methods and apparatuses withinthe scope of the disclosure, in addition to those enumerated herein,will be apparent to a person of ordinary skill in the art from theforegoing descriptions. Portions and features of some embodiments may beincluded in, or substituted for, those of others. Many other embodimentswill be apparent to those of ordinary skill in the art upon reading andunderstanding the description provided herein. Such modifications andvariations are intended to fall within a scope of the appended claims.The present disclosure is to be limited only by the terms of theappended claims, along with the full scope of equivalents to which suchclaims are entitled. It is also to be understood that the terminologyused herein is for the purpose of describing particular embodiments onlyand is not intended to be limiting.

Moreover, the description provided herein includes illustrativeapparatuses (circuitry, devices, structures, systems, and the like) andmethods (e.g., processes, protocols, sequences, techniques, andtechnologies) that embody various aspects of the subject matter. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide an understanding of variousembodiments of the subject matter. It will be evident, however, to thoseskilled in the art that various embodiments of the subject matter may bepracticed without these specific details. Further, well-knownapparatuses and methods have not been shown in detail so as not toobscure the description of various embodiments. Additionally, as usedherein, the term “or” may be construed in an inclusive or exclusivesense.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b), requiring an abstract allowing the reader to quickly ascertainthe nature of the technical disclosure. The abstract is submitted withthe understanding that it will not be used to interpret or limit theclaims. In addition, in the foregoing Detailed Description, it may beseen that various features are grouped together in a single embodimentfor the purpose of streamlining the disclosure. This method ofdisclosure is not to be interpreted as limiting the claims. Thus, thefollowing claims are hereby incorporated into the Detailed Description,with each claim standing on its own as a separate embodiment.

What is claimed is:
 1. An apparatus to repair through-substrate vias,the apparatus comprising: a number of through-substrate vias and atleast an integral number, n, of redundant through-substrate vias; aswitched input and a switched output coupled to respective inputs andoutputs of each of the number of through-substrate vias and the nredundant through-substrate vias, each of the switched inputs and theswitched outputs having a number of switchable inputs and a number ofswitchable outputs, the switched inputs and the switched outputs beingconfigured to switch out a defective one of the number ofthrough-substrate vias with a subsequently located one of thethrough-substrate vias.
 2. The apparatus of claim 1, wherein each of then redundant through-substrate vias is initially configured to be coupledto ground on the respective inputs and to not be coupled on therespective outputs.
 3. The apparatus of claim 1, wherein the integralnumber, n, is two.
 4. A method of repairing a defectivethrough-substrate via, the method comprising: indentifying the defectivethrough-substrate via; disabling an input and an output from thedefective through-substrate via; and shifting the input and the outputfrom the defective through-substrate via to a respective input andoutput of a subsequent through-substrate via.
 5. The method of claim 4,further comprising making a determination whether the subsequentthrough-substrate via is a redundant through-substrate via.
 6. Themethod of claim 5, further comprising based on the determination thatthe subsequent through-substrate via is the redundant through-substratevia, ending the through-substrate via repair.
 7. The method of claim 5,further comprising based on the determination that the subsequentthrough-substrate via is not the redundant through-substrate via,shifting the input and output from the subsequent through-substrate viato a respective input and output of a next subsequent through-substratevia.